QuantiFERON-TB Gold Plus vs. Skin Test: What Phoenix Healthcare Workers Need to Know

Every year, thousands of healthcare workers, nursing students, and new clinical hires in the Phoenix metro area need to demonstrate they are free of tuberculosis before starting. For many years that meant two separate visits — one to receive the skin test, and a return visit 48–72 hours later to have the injection site read. Missing the reading window meant starting over.

The QuantiFERON-TB Gold Plus (QFT-Plus) blood test accomplishes the same purpose in a single visit. One blood draw. Results typically available in 24–48 hours. Accepted at Banner Health, HonorHealth, Dignity Health, and most Arizona healthcare employers and nursing programs.

What Is QuantiFERON-TB Gold Plus?

The QuantiFERON-TB Gold Plus is an IGRA — interferon gamma release assay. It measures how your immune system responds to proteins associated with Mycobacterium tuberculosis, the bacterium that causes TB. When your blood sample is exposed to these proteins in a laboratory setting, your white blood cells release interferon gamma if you have been exposed to TB. The amount released is measured and reported as positive, negative, or indeterminate.

The test is processed through our SAMHSA-certified reference laboratory partners. Results are typically available in 24–48 hours and are delivered securely — HIPAA-compliant throughout.

How It Compares to the TB Skin Test

The tuberculin skin test (TST/Mantoux) requires a provider to inject tuberculin purified protein derivative under the skin of your forearm, followed by a return visit to have the site measured. It has been in use for many decades and remains accepted. However, it has documented limitations that the blood test does not share.

The skin test requires two visits. The QuantiFERON-TB Gold Plus requires one.

The skin test can produce positive results in individuals who received the BCG vaccine — a standard childhood immunization in many countries outside the United States. Phoenix's healthcare workforce includes many professionals from the Philippines, India, Mexico, and other regions where BCG vaccination is routine. Their skin test results may be positive not because of tuberculosis exposure, but because of that prior vaccination. The QFT-Plus is not affected by prior BCG vaccination.

The skin test is read visually by a provider and involves a degree of subjectivity. The blood test is measured in a laboratory.

Who Requires It in Phoenix

Most major Phoenix-area healthcare employers and academic programs accept or prefer the QFT-Plus for TB clearance requirements.

• Hospital system new hires — Banner Health, HonorHealth, Dignity Health, Mayo Clinic, Valleywise, and most hospital staffing agencies
• Nursing and allied health programs — Grand Canyon University, Arizona State University, Maricopa Community Colleges, and most Phoenix-area nursing schools for clinical rotations
• Long-term care and assisted living — Arizona state regulations require TB clearance for new employees in skilled nursing facilities, memory care, and assisted living
• Childcare and school employment — Arizona Department of Health Services requirements apply to many childcare and school positions
• Immigration physicals — the QFT-Plus is accepted for USCIS civil surgeon immigration medical examinations

Walk In at ExpressCare Labs

Walk in Monday through Friday, 8AM to 4PM. Walk-ins accepted until 3:30 PM. No appointment required, though booking ahead is available at expresscarelabs.com.

The QuantiFERON-TB Gold Plus is $115 at ExpressCare Labs. No prior doctor's order required. No insurance needed. Results delivered securely in 24–48 hours.

If you also need immunity titers — MMR, Varicella, Hepatitis B — ExpressCare Labs offers bundle pricing. The MMRV + Hepatitis B + QuantiFERON-TB bundle is $235 and satisfies most hospital and nursing program clearance requirements in a single draw.

Bring a valid government-issued photo ID. The process typically takes under 10 minutes from check-in to leaving.